Increased Ligament Thickness in Previously Sprained Ankles as Measured by Musculoskeletal Ultrasound

Context:Lateral ankle sprains are among the most common injuries in sport, with the anterior talofibular ligament (ATFL) most susceptible to damage. Although we understand that after a sprain, scar tissue forms within the ligament, little is known about the morphologic changes in a ligament after injury.Objective:To examine whether morphologic differences exist in the thickness of the ATFL in healthy, coper, and unstable-ankle groups.Design:Cross-sectional study.Setting:Laboratory.Results:A group-by-limb interaction was evident (P = .038). The ATFLs of the injured limb for the coper group (2.20 ± 0.47 mm) and the injured limb for the unstable group (2.28 ± 0.53 mm) were thicker than the ATFL of the “injured” limb of the healthy group (1.95 ± 0.29 mm) at P = .015 and P = .015, respectively. No differences were seen in the uninjured limbs among groups.Conclusions:Because ATFL thicknesses of the healthy group''s uninjured ankles were similar, we contend that lasting morphologic changes occurred in those with a previous injury to the ankle. Similar differences were seen between the injured limbs of the coper and unstable groups, so there must be another explanation for the sensations of instability and the reinjuries in the unstable group.Key Words: ankle instability, anterior talofibular ligament, morphology

Key Points

• The anterior talofibular ligament can be viewed using musculoskeletal ultrasound imaging.
• The anterior talofibular ligaments of previously sprained ankles were thicker than those of uninjured ankles.
• Although coper ankles were more functionally similar to healthy ankles than to unstable ankles, they were structurally different. Only further research can determine the relationship between ligament damage and functional stability of the ankle.

Musculoskeletal ultrasound (MSUS) imaging is a new technique being used in the sports medicine setting. Compared with other imaging techniques, such as radiographic or magnetic resonance imaging (MRI), MSUS offers a safer, more time-efficient, and more cost-effective alternative. A real-time image can be captured via MSUS by using a transducer to send high-frequency sound waves into the body and recording the echo of the sound waves reflecting back, providing an image of the internal structure.^1,2 This method has been found to be effective in imaging upper extremity, lower extremity, and joint injuries.^1,3,4Oae et al³ reported greater than 90% accuracy for both MSUS and MRI in identifying injuries to the ankle. Lateral ankle sprains (LASs) are among the most common injuries in sport.⁵ An estimated 850 000 new ankle sprains occur each year in the United States,⁷ which does not include a 70% reinjury rate at the ankle.⁶ Ankle stability plays an important role in injury prevention. Passive stability of the ankle is predominantly the responsibility of ligaments supporting the bony structure of the talocrural joint because there are no musculotendinous insertions on the talus. Ligaments supporting the lateral complex of the ankle include the anterior talofibular ligament (ATFL), calcaneofibular ligament, and posterior talofibular ligament. The ATFL is a flat ligament that attaches from the anterior border of the lateral malleolus to the talus, just anterior to the lateral malleolus articular surface.⁸ The ATFL limits plantar flexion and inversion, motions that coincide with the most common mechanism of injury.⁸ As a result, the ATFL becomes vulnerable in a plantar-flexed and inverted position and is most susceptible to damage during an LAS.^5,6,9 An isolated tear of the ATFL occurs in about 80% of LASs.^10,11After an LAS, the fibrous structure of an ankle ligament is often disrupted by severe damage. Using MRI, Takao et al¹² reported visible scarring of the ATFL after injury. Using MSUS, McCarthy et al¹³ described a thickened ATFL, osseous spurs, and synovitic lesions after injury. Thickness values for the ATFL have been derived primarily from cadaveric studies^14,15; however, MRI-based in vivo studies demonstrated thickness of the ATFL to be in the range of 2 to 3 mm.^16,17 An abnormal ligament could affect the stabilizing properties of the ligament. In animal studies, although scar tissue formed within a ligament after injury, the newly scarred ligament allowed normal movement; however, the load capacity of that ligament was decreased by 60%.^18–20 Therefore, the strength of a ligament can be sufficient for active movement and injury rehabilitation soon after injury, but the decrease in load capacity of the scarred ligament may affect its stabilizing properties.Despite medical treatment and postinjury rehabilitation, more than 50% of individuals who sustain a moderate or severe ankle sprain experience some degree of residual disability and impairment due to symptoms such as pain, instability, loss of range of motion, and edema.^6,21 Those who do not fully recover from their ankle sprain often develop chronic ankle instability (CAI), which limits function not only in sport but also in activities of daily living. Patients with CAI typically complain of the ankle “giving way” or of repeated ankle sprains under seemingly low-risk conditions.²²Typically, CAI researchers have categorized participants into 2 groups: those with ankle instability (unstable) and those without ankle instability (healthy). The unstable group consists of individuals who experience recurrent sprains, sensations of instability, or both. Unfortunately, this method of grouping ignores those who sustained an ankle sprain but did not experience recurrent sprains or sensations of instability. In general, an ankle “coper” refers to an individual who has experienced an initial ankle sprain but not a subsequent sprain.²³ Only recently have copers been addressed in ankle-instability research.^24–29 Because copers are still a new cohort in this research, the classification of ankle copers differs somewhat among researchers.^25,28Although we understand that the fibrous nature of a ligament is disrupted after an LAS, little is known about the actual morphologic changes in a ligament. Therefore, the purpose of our study, using a mixed-model analysis, was to determine whether MSUS can be used to see differences in ligament thickness between the uninjured limb and the injured limb among the healthy, coper, and unstable groups. We hypothesized that the ligaments of the previously injured ankles would be thicker than the uninjured ankles.     

Functional tricuspid regurgitation secondary to aortic annular abscess: An unusual presentation of infective endocarditis

An unusual case of aortic annular abscess is presented, in which the patient presented with features of gross tricuspid regurgitation. There was no direct involvement of the tricuspid valve. Tricuspid regurgitation disappeared following surgical repair of the annular abscess. The present case also illustrates the utility of trans-oesophageal echocardiography in establishing the diagnosis and planning surgical intervention.     

Denaturing gradient gel electrophoresis: a novel method for determining Rh phenotype from genomic DNA

Denaturing gradient gel electrophoresis (DGGE) was carried out on PCR products amplified from exons 2 and 5 of RHD and RHCE. Exon 2 of RHD and exon 2 of the C allele of RHCE have an identical sequence, which differs from that of the c allele of RHCE. One band representing D and/or C, and another representing c, could be distinguished by DGGE of exon 2 amplifications of genomic DNA from individuals with the appropriate Rh phenotype. C and c could only be distinguished in D-negative samples. Exon 5 of RHD and exon 5 of the E and e alleles of RHCE all have different nucleotide sequences. Bands representing D, E and e could be distinguished following DGGE of the products of exon 5 amplification of genomic DNA from individuals with red cells of the appropriate Rh phenotype. In samples from individuals with VS+ red cells (V+ or V?) there was a shift of the band representing e. Sequencing demonstrated that VS is associated with a RHCE e sequence with a single base change predicting a Leu245 → Val substitution in the Rh polypeptide. This substitution may be responsible for the VS and e^s antigens.     

Immortalization and characterization of human cell lines with mast cell and monocytic properties

Summary. We have previously derived a cell strain which had both mast cell and monocytic properties from the bone marrow of a child with diffuse cutaneous mastocytosis. This cell strain, termed HBM-M, consisted of two cell populations both of which possessed certain ultrastructural, cytochemi-cal and surface phenotypic features of degranulated mast cells. The cells also displayed cytochemical and surface phenotypic features of monocytes. These cells may represent a common bone marrow derived mast cell/monocyte precursor. Studies of human mast cells have been hindered by the fact that it is difficult to establish such cells in long-term culture. Thus, we sought to immortalize HBM-M cells by introducing Simian virus 40 large T-antigen. Following transfection by the strontium phosphate technique, transformed cells were selected, expanded and passaged until the cells entered a non-proliferative phase termed crisis. Certain clones passed through crisis 3 months later and by this means two immortal cell lines, HBM-MI-1 and HBM-MI-2, were obtained. The criterion for immortality was growth for greater than 100 population doublings. The immortal cell lines retained some, but not all. of the mast cell and monocytic properties of the original HBM-M cell strain. The immortalization of the cell strain HBM-M provides an opportunity to investigate the mast cell and monocytic properties of these cells, and the apparent relationship between mast cells and monocytes.     

Persistence of atovaquone in human sera following treatment: inhibition of Plasmodium falciparum development in vivo and in vitro

Published pharmacokinetic data indicate that after treatment of patients with therapeutic doses of atovaquone/proguanil hydrochloride (Malarone, GlaxoSmithKline Research Triangle Park, NC), the plasma half-lives of these drugs are 70h and 15h, respectively. However, using two biologic assays (mosquito transmission and in vitro asexual stage development), we demonstrate here that sera from volunteers treated with atovaquone/proguanil retained activity against Plasmodium falciparum up to 6 weeks after such treatment. This activity was due to atovaquone, as administration of this drug alone replicated the data obtained with the combination. Most notably, asexual stage development of an atovaquone-resistant strain (NGATV01) of P. falciparum was not inhibited by sera taken after atovaquone treatment. These data indicate that for atovaquone, biologic assays, though not quantitative, are more sensitive than the usual physicochemical assays. Also, persistence of atovaquone in plasma at low concentrations for long periods may increase the risk of resistant parasites arising.     

Radiographic hand joint space width assessed by computer is a sensitive measure of change in early rheumatoid arthritis

OBJECTIVE: To compare changes in the computerized measurement of radiographic hand joint space width (JSW) to changes in modified Sharp scores in a retrospective 2-year study of early rheumatoid arthritis (RA). METHODS: First and last standard clinical hand radiographs of 245 patients with RA were analyzed blind using purpose-written computer software to measure changes in JSW for proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints in the 3 middle fingers of each hand. Before measurement, the radiographs were scored independently by 2 radiologists using a modification of Sharp scoring. RESULTS: The paired changes in JSW (-0.051 +/- 0.005 mm) and Sharp score (+3.81 +/- 0.50) were both significant over the study duration. In measured joints showing an increase in joint space narrowing (JSN) score, 92% had a corresponding reduction in JSW. In patients with an increase in total score, including JSN and erosion scores in fingers and wrists, 84% had a corresponding reduction in mean (PIP + MCP) JSW. Patients with no change in Sharp score (47%) still experienced a significant reduction in measured JSW (-0.027 +/- 0.006 mm). HLA-DR genetic markers of severe disease progression were associated with significantly greater reductions in JSW but not increases in Sharp score. (Values: mean +/- standard error of mean). CONCLUSION: Measured JSW averaged over 6 PIP and 6 MCP joints was a valid and more sensitive measure of change than total Sharp score in this study of early RA.     

Respiratory virus infections in transplant recipients after reduced-intensity conditioning with Campath-1H: high incidence but low mortality

Respiratory virus infections can cause serious morbidity and mortality after conventional allogeneic stem cell transplantation. However, the incidence and outcome of these infections after reduced intensity conditioning has not been reported. Between 1997 and 2001, 35 episodes of respiratory virus infections were noted in 25 of 83 transplant recipients conditioned with fludarabine, melphalan and Campath-1H, and 80% of them received early antiviral therapy. Parainfluenza virus (PIV) 3 was the commonest isolate (45.7%) followed by respiratory syncytial virus (37%). Patients with myeloma were more susceptible to these infections [odds ratio (OR) 4.1, P = 0.01] which were often recurrent in patients with severe acute or chronic graft-versus-host disease (GVHD) (OR 10.6, P = 0.03). Infection within the first 100 d (OR 5.0, P = 0.05) and PIV 3 (OR 9.2, P = 0.01) isolation were risk factors for developing lower respiratory infection. Although more than half of the episodes progressed to lower respiratory infection, the mortality was only 8%. This could have been due to early initiation of antiviral therapy, but the attenuation of pulmonary damage due to the reduced-intensity conditioning, low incidence of GVHD and, paradoxically, the low CD4+ T-cell subset in this setting might also have been contributory factors.